Filter features with TimeSlider

This sample demonstrates how to filter temporal data in a GeoJSONLayer using a TimeSlider widget. This can be done by creating a new FeatureFilter and updating the filter's timeExtent property by watching the changes to the TimeSlider's timeExtent.

When the GeoJSONLayer is initialized, the timeInfo property for the layer is specified as shown below:

Use dark colors for code blocksCopy
1
2
3
4
5
6
7
8
9
10
11
12
 const layer = new GeoJSONLayer({
  ...
  // specify timeInfo for the layer
  timeInfo: {
    startField: "time", // name of the date field
    interval: { // specify time interval for
      unit: "days",
      value: 1
    }
  }
  ...
 });

Then, an instance of the TimeSlider widget is created and added to the view. The additional properties for the TimeSlider are set from the layer's timeInfo information once the layer is loaded.

Use dark colors for code blocksCopy
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
        // create a new time slider widget
        // set other properties when the layer view is loaded
        // by default timeSlider.mode is "time-window" - shows
        // data falls within time range
        const timeSlider = new TimeSlider({
          container: "timeSlider",
          playRate: 50,
          stops: {
            interval: {
              value: 1,
              unit: "hours"
            }
          }
        });
        view.ui.add(timeSlider, "bottom-left");

        const setupTimeSlider = async () => {
          // wait till the layer view is loaded
          const lv = await view.whenLayerView(layer);
          layerView = lv;

          // start time of the time slider - 5/25/2019
          const start = new Date(2019, 4, 25);
          // set time slider's full extent to
          // 5/25/5019 - until end date of layer's fullTimeExtent
          timeSlider.fullTimeExtent = {
            start: start,
            end: layer.timeInfo.fullTimeExtent.end
          };

          // We will be showing earthquakes with one day interval
          // when the app is loaded we will show earthquakes that
          // happened between 5/25 - 5/26.
          let end = new Date(start);
          // end of current time extent for time slider
          // showing earthquakes with one day interval
          end.setDate(end.getDate() + 1);

          // timeExtent property is set so that timeslider
          // widget show the first day. We are setting
          // the thumbs positions.
          timeSlider.timeExtent = { start, end };
        };

Lastly, the application watches the TimeSlider's timeExtent property and the layer's feature effect is updated to show the earthquakes recorded within the current timeExtent of the widget. The application also does statistics query on the earthquakes on that day after the feature effect is applied.

Use dark colors for code blocksCopy
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
// watch for TimeSlider timeExtent change
reactiveUtils.watch(
  () => timeSlider.timeExtent,
  async () => {
    // only show earthquakes happened up until the end of
    // timeSlider's current time extent.
    const date = new Date(timeSlider.timeExtent.end).toISOString().replace("T", " ").replace("Z","");
    layer.definitionExpression = "time <= Timestamp '" + date + "'";

    // now gray out earthquakes that happened before the time slider's current
    // timeExtent... leaving footprint of earthquakes that already happened
    layerView.featureEffect = {
      filter: {
        timeExtent: timeSlider.timeExtent,
        geometry: view.extent
      },
      excludedEffect: "grayscale(20%) opacity(12%)"
    };
);

How it works

The app shows USGS earthquakes recorded between 5/25/2019 - 6/11/2019. The view's extent is set to Pomona, CA area to show earthquakes recorded in this region.

To start visualizing recorded earthquakes in this region you can do one of the following:

  • Hit play button to automatically update the time visualization.
  • Hit next or previous buttons to step through one day at a time.
  • Drag the thumbs or segment to jump through days.

Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.